| 摘要 |
A composition for coating articles of monomolecular organic substances comprises a mixture of (1) an aqueous emulsion of polyvinylidene chloride with predominantly amorphous particles in a proportion of 50-99% by weight, and (2) an aqueous emulsion of polyvinylidene chloride with predominantly crystalline particles in a proportion of 50-1% by weight. The copolymers used contain 70-95% by weight of vinylidene chloride and 30-5% by weight of one or more copolymerizable monomers. Monomers specified are vinyl chloride, acrylonitrile, methacrylonitrile, esters of acrylic, mathacrylic, maleic, fumaric, and itaconic acids with alcohols containing 1-6 carbon atoms, methyl vinyl ketone, vinyl acetate and other vinyl esters, styrene, dichlorovinylidene fluoride, butadiene, chlorobutadiene, isoprene and vinyl pyridine. The dispersion may also contain 0.01-5% of a slip agent such as carnauba wax, spermacetic wax, candellila wax, palm wax, hydrogenated castor oil, benzyl stearate, pentaerythritol distearate, pentaerythritol tetrastearate or n-octadecyl stearate. Specifications 663,645, 679,054, 744,669, 766,827, 804,285 and French Specification 1,254,025 are referred to.ALSO:Sheets of macromolecular organic substances are coated with a composition comprising a mixture of (1) an aqueous dispersion of a vinylidene chloride polymer in a proportion of 50-99% by weight with predominantly amorphous particles and (2) 50-1% by weight of an aqueous dispersion of a vinylidene chloride polymer with predominantly crystalline particles. In the example, an amorphous copolymer of vinylidene chloride/methyl methacrylate/acrylonitrile/itaconic acid and a crystalline copolymer of vinylidene chloride/methyl methacrylate/acrylonitrile/itaconic acid were mixed and applied to foils of regenerated cellulose which had first been coated with glycerine and polyethylene imine, and on foils of polyethylene, polyethylene terephthalate, and of a mixture of polyvinyl chloride and chlorinated polyethylene. The dispersions may also contain a slip agent. Specifications 663,645, 679,054, 744,669, 766,827 and 804,285 are referred to. |
